One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(6,10)(7,12)(13,14)(15,18)(16,19)(17,20)(21,22)(23,24)(25,26)(27,28) involution — undirected(5,6,9,10)(7,11,12,8)(13,15,16,20)(14,17,19,18)(22,26)(23,28)(13,14)(15,18)(16,19)(17,20)(21,23)(22,27)(24,26)(25,28) involution — undirected(1,2)(3,4)(5,7)(6,11)(8,10)(9,12)(13,14)(15,17)(16,19)(18,20)(21,24,25,27)(22,23,26,28)(5,8,9,11)(6,12,10,7)(13,15)(14,18)(16,20)(17,19)(21,23)(22,24)(25,28)(26,27)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.